Numerous oil and/or gas wells present zonal isolation issues. For example, such issues may be in the form of a sustained casing pressure, or similar unwanted hydrocarbon migration issues.
In order to improve long-term zonal isolation, new cement based material having self-healing properties have been developed. Hydrocarbons activate the self-healing blend material whenever the integrity of the cement sheath is compromised by cracks, fissures, or by a micro-annulus. Leakage paths are then sealed thanks to a swelling mechanism.
Self-healing cements (SHCs) are responsive materials. This means that they self-repair. Self-repairing is initiated when a hydrocarbon fluid originating from the formation comes into contact with an exposed surface of the SHC material where, when and if it is needed.
Hence, the self-healing property of cement based materials offers technological solutions to the increasing environmental challenges that the oil and gas industry are currently facing.
Self-healing property was described in the following SPE papers, all of which are incorporated herein in their entireties:
Roth, Talisman Energy, C. Reeves, C. R. Johnson, G. De Bruijn, M. Bellabarba, S. Le Roy-Delage, H. Bulte Loyer, Innovative Hydraulic Isolation Material Preserves Well Integrity IADC/SPE 112715 Drilling Conference held in Orlando, March 2008;
N. Moroni, Eni, N. Panciera, Stogit, C. Johnson, S. LeRoy-Delage, H. Bulte-Loyer, S. Cantini, E. Bellegia and R. Illuminati Overcoming the Weak Link in Cemented Hydraulic Isolation SPE 110523 ATCE, Anaheim., November 2007;
S. Cantini; E. Belleggia; R. Illuminati C. Johnson, S. Le Roy-Delage, H. Bulte-Loyer, An Integrated Approach to Achieve Optimal Zonal Isolation Paper presented at Schlumberger Reservoir Symposium held in Beijing, October 2007;
C. Johnson, S. Le Roy-Delage and H. Bulte-Loyer Managing Zonal Isolation Risk Through Use of a New Responsive Cement Material DOT (Deep Offshore Technology Conference), Stavanger, Norway, Oct. 10-12 2007;
Johnson C. R. Bulte H., Le Roy-Delage S., Illuminati R., Belleggia E., Moroni N., Barbieri E., Self Healing Cement-Novel Technology to Achieve Leak-Free UGS Wells, Communication during SPE Applied Technology Workshop Underground storage of natural gas-today and tomorrow” held in Krakow, Poland, 28-31 May 2007; and
P. Cavanagh, Suncor Energy Inc, C. R. Johnson, S. Le Roy-Delage, G. DeBruijn, I. Cooper, D. Guillot, H. Bulte, B. Dargaud, Schlumberger Self-Healing Cement—Novel Technology to Achieve Leak-Free Wells, SPE/IADC 105781 Drilling Conference Amsterdam, February 2007.
However, the self-healing property are currently difficult to characterize as neither the ASTM (American Society for Testing and Materials), API (American Petroleum Institute) nor ISO (International Organization for Standardization) standards are describing any methodology. These “normalization entities” do not provide any recommendations to characterize this property.